Lawyers seeking a new trial for Kennedy cousin Michael Skakel argued in court papers filed this week that evidence heard at a hearing in April showed Skakel's trial lawyer "had a good time" with the case at the expense of the convicted murderer's defense and freedom.

At Skakel's high-profile 2002 trial, defense lawyer Mickey Sherman "forgot the cardinal rule – the case is not about the lawyer, it is about the client and his defense," Skakel's current lawyers, Hubert J. Santos and Jessica M. Santos, wrote in a memorandum filed Monday in Superior Court in Rockville.

"Defending a murder charge is not about enjoying oneself, it is about zealously advocating for the client and providing him with the assistance guaranteed by our constitution," the lawyers wrote.

The issue of whether Sherman was obsessed with his own celebrity at Skakel's expense was at the heart of Skakel's two-week hearing in April on his petition for a writ of habeas corpus. Such a petition is often a convict's last resort to get a verdict overturned or a prison sentence reduced.

Skakel was convicted following his 2002 trial for the 1975 murder of his Greenwich neighbor, 15-year-old Martha Moxley, in the town's exclusive Belle Haven section. Moxley was bludgeoned to death, with part of a golf club shaft driven through her neck.

Skakel, 52, the nephew of Robert and Ethel Skakel Kennedy, is serving a sentence of 20 years to life. The state Supreme Court has upheld his conviction and the U.S. Supreme Court has declined to review the case.

In his petition, Skakel said Sherman was ineffective at trial and failed to present important evidence that could have led to his acquittal. His new lawyers during the April hearing portrayed Sherman as a money-hungry lawyer with financial woes who spent time in the media spotlight and at "A-list" parties instead of on Skakel's defense strategy.

Sherman countered Skakel's allegations, saying he never skimped on spending money and time on Skakel's defense, saying he had appeared on TV as a legal analyst "way before" he took on the Skakel case in the late 1990s.

He said at the time of the trial, Skakel "approved" of his media appearances and "never complained about it."

The papers filed by the defense Monday also point to evidence that the defense says shows that Sherman's failure to obtain a police sketch of a man seen near Moxley's home the night she was killed hurt Skakel's case.

Skakel's lawyers said Sherman did not specifically request a copy of the sketch, which bears a strong resemblance to a former suspect in Moxley's murder.

The state Supreme Court, in upholding Skakel's conviction in 2006, said the state should have turned over the sketch. But because the sketch is mentioned in two reports that Sherman had in his possession before trial, the high court deemed it a harmless error, because Sherman had notice of the existence of the sketch and did not pursue it.

Sherman said during his testimony in April that "I think it would have helped his defense to have the sketch. I think it would have raised reasonable doubt."

The state has 30 days to respond to the defense's post-hearing brief. A decision by Judge Thomas Bishop could come by late summer. If Bishop rules in Skakel's favor, prosecutors would have to decide whether they want to try the case again.